给排水方面的英文资料

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给排水方面的英文资料 History of Water Supply Man’s search for pure water began in prehistoric times. Much of his earliest activity is subject to speculation. Some individuals might have led water where they wanted it through trenches dug in the earth, a hollow log was perhaps used as the first water pipe. Thousands of years must have passed before our more recent ancestors learned to build cities and enjoy the convenience of water pipes to the home and drains for water-carried wastes. Our earliest archeological records of central water supply and wastewater disposal date back about 5000 years, to Nippur of Sumeria. In the ruins of Nippur there is an arched drain with the stones set in full "voussoir" position, each stone being a wedge tapering downward into place. Water was drawn from wells and cisterns.An extensive system of drainage conveyed the wastes from the palaces and residential districts of the city. The earliest recorded knowledge of water treatment is in the Sanskrit medical lore and Egyptian Wall inscri ptions. Sanskrit writings dating about 2000 B.C. tell how to purify foul water by boiling in copper vessels,exposing to sunlight, filtering through charcoal, and cooling in an earthen vessel. The earliest known apparatus for clarifying liquids was pictureed on Egyptian walls in the fifteenth and thirteenth centuries B.C. The first picture represents the siphoning of either water of settled wine. A second picture shows the use of wick siphons in an Egyptian kitchen. The first engineering report on water supply and treatment was made in A.D. 98 by Sextus Julius Frontinus, water-commissioner of Rome. He produced two books on the water supply of Rome. In these he described a settling reservoir at the head of one of the aqueducts. His writings were first translated into English by the noted hydraulic engineer Clemens Herschel in 1899. In the eight century A.D. an Arabian alchemist,Geber,wrote a rather specialized treatise on distillation that included various stills for water and other liquids. The English philosopher Sir Francis Bacon wrote of his experiments on the purification of water by filtration, boiling, distillation and clarification by coagulation. This was published in 1627, one year after his death. Bacon also noted that clarifying water trends to improve health and increase the "pleasure of the eye". The first known illutrated descri ption of sand filters was published in 1685 by Luc Antonio Porzio, an Italian physician. He wrote a book on conserving the health of soldier in camps, based on his experience in the Austro-Turkish War. This was probably the earliest published work on mass sanitation.He described and illustrated the use of sand filters and sedimentation. Porzio also stated that his filtration was the same as "by those who built the wells in the Palace of the Doges in Venice and in the palace of Cardinal Sachett,at Rome." The oldest known archeological examples of water filtration are in Venice and the colonies she occupied. The ornate heads on the cisterns bear dates,but it is not known when the filters were placed.Venice,Built on a Series of islands, depended on catching and storing rainwater for its principal freshwater supply for over 1300 years. Cisterns were built and many were connected in stone-grated catch basins and then filtered through sand into cisterns. A comprehensive article on the water supply of Venice appeared in the Practical Mechanics Journal in 1863.The land area of Venice was 12.85 acres and the average yearly rainfall was 32 inches(in). Nearly all of this rainfall was collected in 177 public and 1900 private cisterns. These cisterns provided a daily average supply of about 4.2 gallons per capita per day(gpcd).This low consumption was due in part to the absence of sewers, the practice of washing clothes in the lagoon,and the universal drinking of wine. These cisterns continued to be the principal water supply of Venice until about the sixteenth century. Many experiments were conducted in the eighteenth and nineteenth centuries in England,France Germany,and Russia.Henry Darcy patented filters in france and England in 1865 and anticipated all aspects of the American rapid sand filter except coagulatin.He appears to be the first to apply the law of hydraulics to filter design. The first filter to supply water to a whole town was completed at Paisley,Scotland,in 1804,but this water was carted to consumers. In Glasgow, Scotland,in 1807 filtered water was piped to consumers. In the United States little attention was given to water treatment until after the Civil War. Turbidity was not as urgent a problem as in Europe. The first filters were of the slow sand type,similar to British design. About 1890 rapid sand filters were developed in the United States and coagulants were introduced to increase their efficency. These filters soon evolved to our present rapid sand filters with slight modification.